There are ten caverns in total, each named after one of the Sephirot (also known as the nodes in the Tree of Life). Each cavern contains a shrine. Meditating at a shrine (costs 50AP) will double your HP (capped at full heal) and increase your to-hit by 3% (once a weapon has a 90% to hit, each further 10% bonus to hit will only grant a +1% to hit, capped at 99%).

There are twenty-two paths between the caverns, each of which requires the use of a different Tarot Card (the card is consumed when travelling between the caverns, also costs 10AP). Please note, after you hit up all the locations you are not able to walk freely between them, so please plan your trip accordingly.

Meditate at all 10 altars in the Caverns to qualify for joining the Bomb Squad. Joining the Bomb Squad costs 100AP and 1500GP (at the Bomb Squad office, 44E 66S).

The Caverns are infested with small and normal sized demons of all alignments. Most of their attacks can permanently harm your stats (e.g. Fire Demons drain your to-hit, Earth Demons drain your strength). If you are not keen on fighting demons, bring a cloak/clock of invisibility/One Bling, use kraken pieces liberally, or travel with adventurers of the same alignment to share the risk of using wands. (Note that large demons can see invisible players. Keep this in mind when running the Caverns.) If you are a wizardly-type, then casting Toad Spells can get you past nasty creatures. Non-wizards can do this with Eye Pods, of course, but you will need to cast the spell several times, as each casting only lasts 115AP or so.

You cannot be summoned from the caverns, nor can you be summoned in. If you take a bad turn and end up stuck, you can talisman (or die, of course) to leave.

One useful strategy for all players attempting this would be to switch to uniform alignments, such that those going after might have a chance to avoid the demons again. Also, one might note that being fire aligned is quite possibly the most useful here, as accuracy is the most useful player attribute.